US3673534A

US3673534A - Double life light bulbs, fuses, and the like

Info

Publication number: US3673534A
Application number: US140194A
Authority: US
Inventors: Robert C Marinace
Original assignee: Individual
Current assignee: Individual
Priority date: 1971-05-04
Filing date: 1971-05-04
Publication date: 1972-06-27
Anticipated expiration: 1989-06-27
Also published as: DE2221854A1; IT958564B; NL7205975A; FR2135244A1; GB1337538A

Abstract

Double life light bulbs, fuses, and the like comprising a plurality of conducting filaments arranged in parallel having a common lead and a base comprising a hollow threaded member electrically connected to the common lead; an insulating member with open channels extending therethrough disposed in the lower end of said threaded member; a plurality of conducting members, each having an end connected, respectively, to one of the conducting filaments and the other end extending through the insulating member; and two contact members of ductile, conductive material, said contacts being bent through a 90* angle and being mounted on the exterior of the insulated section of said threaded member with the lines of fold of the respective contact members lying adjacent to one another, the vertically projecting sections of the contacts laminated together in an insulated relationship, the mounted section of the contacts having openings therein for receiving the respective conducting members; the insulated laminate structure being capable of being folded through 180* to expose, alternately, each of the available contacts.

Description

United States Patent Marinace [451 June 27, 1972 Robert C. Marinace, 2440 Valentine Ave., New York, NY. 10458 22 Filed: May4, 1971 211 Appl.No.: 140,194

[72] Inventor:

[52] US. Cl ..337/258, 313/316, 315/64,

339/146 [51] Int. Cl. ..I-l0lh 85/20, H0lk l/64, H0lk 9/04 [58] Field ofSearch ..313/272,3l6,3l8;3l5/64,

Primary Examiner-T. E. Lynch Assistant ExaminerDewitt M. Morgan AttorneyThomas B. Graham ABSTRACT Double life light bulbs, fuses, and the like comprising a plurality of conducting filaments arranged in parallel having a common lead and a base comprising a hollow threaded member electrically connected to the common lead; an insulating member with open channels extending therethrough disposed in the lower end of said threaded member; a plurality of conducting members, each having an end connected, respectively, to one of the conducting filaments and the other end extending through the insulating member; and two contact members of ductile, conductive material, said contacts being bent through a 90 angle and being mounted on the exterior of the insulated section of said threaded member with the lines of fold of the respective contact members lying adjacent to one another, the vertically projecting sections of the contacts laminated together in an insulated relationship, the mounted section of the contacts having openings therein for receiving the respective conducting members; the insulated laminate structure being capable of being folded through 180 to expose, alternately, each of the available contacts.

13 Claims, 7 Drawing figures PATENTEnJuxz'lmz FIGZ FIGS

INVENTOR. ROBERT c. MARINACE ATTORNEY DOUBLE LIFE LIGHT BULBS, FUSES, AND THE LIKE BACKGROUND OF THE INVENTION Dual filament light bulbs, e.g. three way bulbs and automobile taillights, are well known in the art. Such bulbs contain a plurality of contacts which can be simultaneously engaged to energize the desired number of filaments. Once a filament is burned out, however, it is necessary to replace the entire bulb.

Dual filament light bulbs wherein only one of the filaments are energized at any one time, thereby doubling the life expectancy of the bulb, have been disclosed, for example, in British Pat. No. 297,833, U.S. Pat. No. 966,812 and U.S. Pat. No. 3,296,400. The critical component of the bulb disclosed in the British patent is an internal semiconductor junction which breaks down electrically in response to the open circuit created by the destruction of filament No. l and thereby automatically connects filament No. 2.

There are, however, several outstanding disadvantages with this assembly. Initially, it is impossible to test each of the circuits in the bulb subsequent to manufacture inasmuch as the existence of one circuit depends upon thedestruction of the other. Furthermore, any malfunction in the automatic switchover mechanism of the bulb nullifies its entire effectiveness. The internal positioning of the mechanism also necessitates an increase in the manufacturing costs.

U.S. Pat. No. 966,812 teaches the construction of a light bulb incorporating a pair of filaments arranged in electrical parallel relationship and connected with a pair of base contacts. The base contacts are disposed in overlying and underlying relationship so that only one of the contacts is in engagement with the contact in the socket at any one time. As taught therein, the overlying contact is left intact until the filament connected therewith is destroyed. When this occurs, the overlying contact is removed, exposing the underlying contact whereby the second filament can be energized.

The disadvantages in this light bulb structure include the inability to test both filament circuits prior to use due to the mutually exclusive operation of the circuits; the undesirable internal positioning of the conductor to contact junctions; and the uneconomical production costs that are encountered.

U.S. Pat. No. 3,296,400 teaches the construction of a dual filament bulb which utilizes a plurality of stacked contact members insulated from each other, each contact member having an opening therein for receiving at least one of the conductor means attached to the filaments. When one of thefilaments is burned out, the outermost contact member and attached insulation is broken off thereby exposing the underlying contact member and allowing for the energizing of a second filament.

This bulb construction also exhibits certain disadvantages. As in the case of the other prior art structures, it is impossible to test each of the filament circuits subsequent to manufacture inasmuch as only one operable circuit is accessible for testing at any one time. Furthermore, due to the manner in which the contacts are separated from the base structure, there is the likelihood that one or more of the contacts may be inadvertently broken off as, for example, during insertion into a defective socket, thereby reducing the reliability and effectiveness of this bulb construction.

SUMMARY OF THE INVENTION It is the primary object of this invention to provide an improved light bulb having a useful life which is approximately twice that of commercially available light bulbs.

It is a further object to provide a double filament light bulb which substantially overcomes the disadvantages inherent in the prior art double filament bulbs.

Another object is to provide an inexpensive and reliable switchover contact mechanism for the bulb which allows for the independent testing of each filament circuit subsequent to the assembling of the bulb.

Still another object is to adapt the switchover contact mechanism for use with other multi-conductive element constructions.

Various other objects and advantages of this invention will become apparent from the following detailed description thereof.

I have now discovered that it is possible to substantially overcome the disadvantages inherent in the prior art dual filament light bulb constructions by providing the light bulb with a base containing a novel switchover contact mechanism. This mechanism consists of two contact members of ductile, conductive material which are bent through a angle and then mounted on the base of the bulb such that the lines of fold of the respective contact members are adjacent to one another. The vertically projecting sections are then laminated together in an insulated relationship either by the use of an insulating adhesive or by the insertion of an insulating wafer between the vertical sections and their subsequent bonding. The insulated laminate structure is capable of being rotated through in order to fully expose either of the available contact members and energize the filament circuit passing through the contact.

It is to be noted that the simplicity of this mechanism as well as its external mounting on the bulb lend themselves to the ready and economical manufacture of the bulb. They also insure that the bulb will exhibit maximum efficiency and reliability. Of great significance, the simultaneous availability of both contact members and the circuits passing therethrough allows for the testing of both circuits subsequent to manufacture and prior to commercial use. Thus, access to the second circuit is not dependent upon the destruction of the first. These factors together with the extended useful life of the bulb, clearly illustrate the distinct advantages of the novel construction of this invention.

The invention is more specifically defined in the appended claims read together with the following description and accompanying drawings in which:

FIG. 1 is an enlarged cross-sectional view of a light bulb constructed in accordance with this invention;

FIG. 2 is an enlarged perspective view depicting the novel switchover contact mechanism of the invention;

FIG. 3 is a view partly in cross-section and partly in elevation of the mounted switchover contact mechanism shown in FIG. 2;

FIGS. 4 and 5 are bottom plan views of the fully exposed contact members of the mechanism shown in FIG. 2;

FIG. 6 is an enlarged cross-sectional view of a fuse constructed in accordance with this invention; and

FIG. 7 is a view partly in cross-section and partly in elevation depicting another switchover contact mechanism constructed in accordance with this invention.

Referring now to the drawings, FIG. 1 shows a light bulb 10 constructed in accordance with the invention. As illustrated, the light bulb 10 includes a glass globe 11 having a neck portion 12 that is closed at its lower end. A support portion 13 extends upwardly from the lower end of the neck portion 12 to support a first conductor 14, a second conductor 15, and a third conductor 16.

As clearly illustrated in FIG. 1, the conductors l4, l5 and 16 extend through the support portion 13 with the upper ends thereof disposed within the globe 11. The lower ends of the conductors l4, 15, 16 are connected as will be described hereinafter.

The conductors l4, 15, 16 support and electrically connect a first filament l7 and a second filament 18. Filament 17 has one end connected with the first conductor 14 and the other end connected with the conductor 16. Filament 18 has one end connected with the conductor 15 and the other end connected with the conductor 16.

The light bulb 10 also includes a base 19 which contains a hollow threaded-member 20 that has an upper end 21 connected with the neck portion 12 of the globe 11. An insulating member 22 is disposed in a lower end 23 of the threaded member 20. The conductor 16, as previously mentioned, is connected at its upper end with both the filaments 17 and 18, and extends downwardly through the support 13 and outwardly through the neck portion 12 of the globe 11. The exposed end of the conductor 16 is soldered, as indicated at 24,

to the upper end 21 of the threaded member 20. Thus, the conductor 16 forms a common return lead for electrical energy passing through either the filament 17 or the filament 18.

The lower end of conductor 14 extends through insulating member 22 and is soldered to the exterior of first contact 25. Likewise, the lower end of conductor 15 extends through insulating member 22 and is soldered to the exterior of second contact 26.

The details of construction of the contact assembly are more clearly illustrated in FIG. 2. As shown therein, the contact assembly consists of two

circular contacts

25, 26. Each

contact

25, 26 is bent at its diameter to form a 90 angle between

horizontal sections

27, 28 and

vertical sections

29, 30. The

horizontal'sections

27, 28 are mounted on the exterior of the insulated section of said threaded member with their respective diameters lying adjacent one another and are provided with

openings

31, 32 for receiving conducting members l4, 15, respectively. The

vertical sections

29, 30 are adhered to one another in an insulated relationship. Such an insulated relationship may be achieved by applying an insulating adhesive (not shown) between the

vertical sections

29, 30 to electrically insulate the

vertical sections

29, 30 from each other while simultaneously adhering them. The preferred method for joining the

vertical sections

29, 30 is by placing an insulated wafer 33 between

vertical sections

29, 30 and adhering the three lamina thereby forming an insulated laminate structure 34. It is to be noted that the insulated member 33 extends beyond the periphery of the

vertical contact sections

29, 30 in order to insure total insulation between said

vertical sections

29, 30.

The contact members are prepared from ductile, conductive materials, such as brass, copper, aluminum and the like. The insulated adhesives are typically based on vinyl-rubber, epoxies, cellulose acetate, polyvinylidene chloride, polyethylene, and the like, while the insulating wafer may be rubber, plastics such as polyethylene and polypropylene, and the like.

As depicted in FIGS. 3, 4 and 5, it is seen that laminate structure 34 can be turned through l80 to expose, altematively, each of the

available contact members

25, 26. Thus, the laminate structure 34 can be bent so as to place horizontal section 28 and vertical section 30 of contact 26 in face-to-face contact, thereby totally exposing contact member 25 (FIG. 4). Likewise, the laminate structure may be bent in the other direction to place horizontal section 27 and vertical section 29 of contact member 25 in face-to-face contact, thereby totally exposing contact member 26 (FIG.

The light bulb is utilized with a threaded socket (not shown) having a threaded wall portion forming one electrical contact and a center contact insulated from the threaded wall forming a second contact. The structure of such sockets is well known to those skilled in the art. The bulb 10, with laminate structure 34 being positioned to expose only contact member 25 (FIG. 4), is screwed into the threaded socket, such that contact member 25 engages the center contact of the socket and an electrical circuit is completed through conductor 14, filament l7, conductor 16 and the threaded member 20. Thus, filament 17 is engaged to emit light.

When the filament 17 has burned out, or is otherwise destroyed, thereby breaking the electrical circuit, the bulb 10 is removed from the threaded socket, the insulated laminate member 34 is rotated through 180 to totally expose contact 26 and the bulb is replaced in the threaded socket. In this manner, contact member 26 engages the center contact in the socket to complete an electrical circuit through conductor 15, filament l8, conductor 16 and threaded member 20. Thus, filament 18 is energized to emit light.

Accordingly, it is to be noted that the novel bulb construction of this invention has a useful life which is approximately twice that of the currently available bulbs. The bulb may be readily and economically manufactured. Of great importance, each of the filament circuits may be tested subsequent to manufacture merely by proper positioning of the laminate structure and energizing of the exposed circuit and, thereafter, positioning the laminate structure in the opposite position and energizing the second circuit.

FIG. 6 illustrates in detail the structure of a fuse generally designated by the reference character 50 and also constructed in accordance with the invention. As shown therein, the fuse 50 includes a hollow body 51 constructed from an insulating material, a pair of

fuse elements

52 and 53 positioned in the interior of the hollow body 51 and a cover 54 extending across the top of the interior of the hollow body 51. The cover 54 is preferably constructed from a transparent material, such as glass or plastic, to permit observation of the

fuse elements

52 and 53.

The base 19, (FIG. 1) is illustrated in combination with the hollow body 51 to form the fuse 50. Thus, the upper end 21 of the threaded member 20 is connected with the lower closed end of the hollow body 51. The threaded member 20 forms a portion of the base 19 previously described in detail in connection with the embodiment of FIG. 1. The base 19 also includes the insulating member 22 extending across the lower end 23 of the threaded member 20.

Mounted on the exterior of the insulated section 22 of said threaded member 20 is the contact assembly 55, as depicted in FIG. 2. As previously noted, the basic components of the contact assembly 55 are the

contact members

25, 26 containing

horizontal sections

27, 28,

openings

31, 32 for receiving the conducting

members

56, 57 and

vertical sections

29, 30 which are bonded together with insulating wafer 33 to form movable insulated laminate structure 34.

The conductor 56 extends from its soldered connection with the contact 25 upwardly, through the body 51 and has its opposite end electrically connected with the fuSe element 52. The conductor 57 extends upwardly from its external connection with the contact 26, through the insulating member 22 and the hollow body 57 and has its opposite end connected with the fuse element 53. The other end of each of the

fuse elements

52 and 53 is connected with a conductor 58 that extends through the hollow body 51 and has its other end connected with the upper end 21 of the threaded member 20 to form a common return lead.

To utilize the fuse 50, the threaded member 20 is screwed into a threaded socket (not shown) having a center contact and a threaded sleeve forming a second contact. With the laminate structure 34 in position to totally expose contact member 25, contact member 25 engages the center contact of the socket to complete the electrical circuit through conductor 56, fuse element 52, and the conductor 58 through the engagement of the threaded member 20 with the threaded sleeve.

If an overload occurs in the circuit, the fuse element 52 separates breaking the circuit and interrupting the flow of current. In order to remedy this situation, it is merely necessary to unscrew the fuse 50, rotate the laminate structure 34 to totally expose contact member 26, and replace the fuse 50. In this manner, contact 26 engages the center contact of the socket to complete an electrical circuit through conductor 57, fuse element 53, and the conductor 58 through threaded member 20.

As with the previously described bulb construction, this novel fuse construction exhibits a useful life which is approximately twice that of conventional fuses, can be readily and economically manufactured, and can have both of its circuits tested subsequent to manufacture.

FIG. 7 illustrates a modified form of switchover contact assembly that can be utilized with bulb 10 (FIG. 1) or fuse 50 (FIG. 6). Thus, contact members 71, 72 are mounted on the exterior of the insulated section of threaded member 73, said contact members 71, 72 being spaced from one another to form slot 74. The specified conducting members pass through openings in contact members 71, 72 and are externally soldered thereto at 75 and 76, respectively. An insulating flap 77 of at least equal size to contact members 71, 72 is inserted in the slot 74, said insulating flap 77 being fitted with a retaining means to retain it in slot 74. The retaining means must also enable the insulating flap 77 to be flipped through 180. Accordingly, the retaining means may be a hinge (not shown) permanently mounted on the insulated section of threaded member 73, said hinge either being an integral part of insulating flap 77 or externally connected to the insulating flap 77. Likewise, the retaining means may be a cylindrical edge 78 (FIG. 7) on insulating flap 77 whose diameter is larger than the distance between contact members 71, 72 at their upper surface. It should be noted that in order to house the latter retaining means, it is necessary that the inward facing sides of contact members. 71, 72 be tapered such that the crosssectional area of slot 74 increases progressively in a downward direction. In this manner, the insulating flap 77 is retained in slot 74 but has sufficient freedom of movement to be flipped through 180.

Operation of bulb 10 or fuse 50 utilizing switchover contact assembly 70 is virtually identical to the mode of operation when utilizing the contact mechanism depicted in FIGS. 1-6. Thus, in order to make the circuit passing through contact member 71 available for energizing, it is merely necessary to position insulating flap 77 so that it completely covers contact member 72. Likewise, the circuit passing through contact member 72 may be made available for energizing by flipping insulating flap 77 in the opposite direction to completely cover contact member 71. It is seen that bulb or fuse constructions utilizing switchover contact mechanism 70 exhibit advantages comparable to those obtained with the contact mechanism depicted in FIGS. 1-6.

Summarizing, it is seen that this invention provides novel double life light bulbs, fuses and the like. It should be understood that the present invention is not limited to the embodiments specifically described herein, but extends to equivalent embodiments utilizing the principles herein disclosed as defined by the following claims.

What is claimed is:

1. A base for light bulbs, fuses, and the like which contain a plurality of conducting elements arranged in parallel and having a common lead, said base comprising a hollow threaded member electrically connected to said common lead and being mounted on one end of the bulb; an insulating member disposed in the lower end of said threaded member; a plurality of conducting members, each having one end electrically connected to a respective one of the conducting elements and the other end extending through said insulating member; and two contact members, each being bent and being mounted on the exterior of the insulating member of said threaded member with their respective lines of fold lying adjacent one another, thesections of said contact members in direct contact with said insulating member having an opening extending therethrough for receiving at least one of said conducting members, said mounted contact sections being electrically connected to said conducting members, the projecting sections of said contact members being laminated together in an insulated relationship to form an insulated laminate assembly, said insulated laminate assembly being capable of being rotated through 180 to fully expose and make available, alternately, each of the contact members.

2. The base of claim 1, wherein the insulated relationship in said insulated laminate assembly is achieved by bonding the projecting contact sections by means of an insulating adhesrve.

3. The base of claim 1, wherein said insulated relationship in said insulated laminate assembly is achieved by inserting an insulating wafer between said projecting contact sections and then bonding the three lamina.

4. An incandescent light bulb comprising an evacuated hollow globe member having a neck portion; first, second and third conductor members each having one end disposed within said globe member and the other end projecting from said neck portion; first and second filament elements disposed in said globe member, each having one end connected with said third conductor member to form a common return, the

other end of said first filament element being connected with said first conductor member and the other end of said second filament element being connected with said second conductor member, whereby said filament elements and conductor members are connected in electrical parallel relationship; a hollow threaded member having one end attached to said neck portion and electrically connected with said third conductor member; an insulating member disposed in the lower end of said threaded member having said first and second conductor members extending therethrough; and two contact members each being bent and being mounted on the exterior of the insulating member of said threaded member with the respective lines of fold lying adjacent one another, the sections of said contact members in direct contact with said insulating member having an opening extending therethrough for receiving at least one of said first and second conducting members, said mounted contact sections being electrically connected to said conducting members, the projecting sections of said contact members being laminated together in an insulated relationship to form an insulated laminate assembly, said insulated laminate assembly being capable of being rotated through to fully expose and make available, alternately, each of the contact members.

5. The light bulb of claim 4, wherein the insulated relationship in said insulated laminate assembly is achieved by bonding the projecting contact sections by means of an insulating adhesive.

6. The light bulb of claim 4, wherein said insulated relationship in said insulated laminate assembly is achieved by inserting an insulating wafer between said projecting contact sections and then bonding the three lamina.

7. A fuse comprising a hollow body member constructed from an insulating material and having a closed end; first and second fuse elements mounted in said body member and disposed in the hollow portion thereof; first, second and third conductor members extending through the closed end of said body member, said third conductor member being connected with one end of each of said fuse elements to form a common return, the other end of said first fuse element being connected with said first conductor member and the other end of said second fuse element being connected with said second conductor member, whereby said fuse elements and conductor members are connected in electrical parallel relationship; a hollow threaded member having one end attached to said closed end and electrically connected with said third conductor member; an insulating member disposed in the lower end of said threaded member and having said first and second conductor members extending therethrough; and two contact members, each being bent and being mounted on the exterior of the insulating member of said threaded member with their respective lines of fold lying adjacent one another, the sections of said contact members in direct contact with said insulating member having an opening said insulated therethrough for receiving at least one of said first and second conducting members, said mounted contact sections being electrically connected to said conducting members, the projecting sections of said contact members being laminated together in an insulated relationship to form an insulated laminate assembly, said insulated laminate assembly being capable of being rotated through 180 to fully expose and make available, alternately, each of the contact members.

8. The fuse of claim 7, wherein the insulated relationship in said insulated laminate assembly is achieved by bonding the projecting contact sections by means of an insulating adhesive.

9. The fuse of claim 7, wherein said insulated relationship in said insulated laminate assembly is achieved by inserting an insulating wafer between said projecting contact sections and then bonding the three lamina.

10. A base for light bulbs, fuses, and the like which contain a plurality of conducting elements arranged in parallel and having a common lead, said base comprising a hollow threaded member electrically connected to said common lead and being mounted on one end of the bulb; an insulating member disposed in the lower end of said threaded member; a plurality of conducting members, each having one end electrically connected to the respective one of the conducting elements and the other end extending through said insulating member; and two contact members being mounted on the exterior of the insulating member of said threaded member and spaced apart to form a slot therebetween, said contact members having an opening extending therethrough for receiving at least one of said conducting members, said contact members being electrically connected to said conducting members, said slot having an insulating flap fitted with a retaining means positioned therein, said insulating flap being of at least equal size to said contact members, said insulating flap being capable of being rotated through 180 to fully expose and make available, alternately, each of the contact members.

11. The base of claim 10, wherein said retaining means for said insulated flap is a hinge member attached thereto which is also mounted between said contact members on the insulated section of said threaded member.

12. The base of claim 10, wherein said insulated flap has a cylindrical edge having a diameter which is larger than the distance between said contact members at their upper surface,

and wherein the inward facing sides of said contact members I are tapered such that the cross-sectional area of said slot increases progressively in a downward direction.

13. A base comprising a hollow threaded member; an insulating member disposed in the lower end of said threaded member; and two contact members being mounted on the ex--

Claims

1. A base for light bulbs, fuses, and the like which contain a plurality of conducting elements arranged in parallel and having a common lead, said base comprising a hollow threaded member electrically connected to said common lead and being mounted on one end of the bulb; an insulating member disposed in the lower end of said threaded member; a plurality of conducting members, each having one end electrically connected to a respective one of the conducting elements and the other end extending through said insulating member; and two contact members, each being bent and being mounted on the exterior of the insulating member of said threaded member with their respective lines of fold lying adjacent one another, the sections of said contact members in direct contact with said insulating member having an opening extending therethrough for receiving at least one of said conducting members, said mounted contact sections being electrically connected to said conducting members, the projecting sections of said contact members being laminated together in an insulated relationship to form an insulated laminate assembly, said insulated laminate assembly being capable of being rotated through 180* to fully expose and make available, alternately, each of the contact members.

2. The base of claim 1, wherein the insulated relationship in said insulated laminate assembly is achieved by bonding the projecting contact sections by means of an insulating adhesive.

4. An incandescent light bulb comprising an evacuated hollow globe member having a neck portion; first, second and third conductor members each having one end disposed within said globe member and the other end projecting from said neck portion; first and second filament elements disposed in said globe member, each having one end connected with said third conductor member to form a common return, the other end of said first filament element being connected with said first conductor member and the other end of said second filament element being connected with said second conductor member, whereby said filament elements and conductor members are connected in electrical parallel relationship; a hollow threaded member having one end attached to said neck portion and electrically connected with said third conductor member; an insulating member disposed in the lower end of said threaded member having said first and second conductor members extending therethrough; and two contact members each being bent and being mounted on the exterior of the insulating member of said threaded member with the respective lines of fold lying adjacent one another, the sections of said contact members in direct contact with said insulating member having an opening extending therethrough for receiving at least one of said first and second conducting members, said mounted contact sections being electrically connected to said conducting members, the projecting sections of said contact members being laminated together in an insulated relationship to form an insulated laminate assembly, said insulated laminate assembly being capable of being rotated through 180* to fully expose and make available, alternately, each of the contact members.

7. A fuse comprising a hollow body member constructed from an insulating material and having a closed end; first and second fuse elements mounted in said body member and disposed in the hollow portion thereof; first, second and third conductor members extending through the closed end of said body member, said third conductor member being connected with one end of each of said fuse elements to form a common return, the other end of said first fuse element being connected with said first conductor member and the other end of said second fuse element being connected with said second conductor member, whereby said fuse elements and conductor members are connected in electrical parallel relationship; a hollow threaded member having one end attached to said closed end and electrically connected with said third conductor member; an insulating member disposed in the lower end of said threaded member and having said first and second conductor members extending therethrough; and two contact members, each being bent and being mounted on the exterior of the insulating member of said threaded member with their respective lines of fold lying adjacent one another, the sections of said contact members in direct contact with said insulating member having an opening said insulated therethrough for receiving at least one of said first and second conducting members, said mounted contact sections being electrically connected to said conducting members, the projecting sections of said contact members being laminated together in an insulated relationship to form an insulated laminate assembly, said insulated laminate assembly being capable of being rotated through 180* to fully expose and make available, alternately, each of the contact members.

10. A base for light bulbs, fuses, and the like which contain a plurality of conducting elements arranged in parallel and having a common lead, said base comprising a hollow threaded member electrically connected to said common lead and being mounted on one end of the bulb; an insulating member disposed in the lower end of said threaded member; a plurality of conducting members, each having one end electrically connected to the respective one of the conducting elements and the other end extending through said insulating member; and two contact members being mounted on the exterior of the insulating member of said threaded member and spaced apart to form a slot therebetween, said contact members having an opening extending therethrough for receiving at least one of said conducting members, said contact members being electrically connected to said conducting members, said slot having an insulating flap fitted with a retaining means positioned therein, said insulating flap being of at least equal size to said contact members, said insulating flap being capable of being rotated through 180* to fully expose and make available, alternately, each of the contact members.

12. The base of claim 10, wherein Said insulated flap has a cylindrical edge having a diameter which is larger than the distance between said contact members at their upper surface, and wherein the inward facing sides of said contact members are tapered such that the cross-sectional area of said slot increases progressively in a downward direction.

13. A base comprising a hollow threaded member; an insulating member disposed in the lower end of said threaded member; and two contact members being mounted on the exterior of the insulating member of said threaded member and spaced apart to form a slot therebetween, said contact members having an opening extending therethrough for receiving at least one conducting member, said contact members being electrically connected to said conducting members, said slot having an insulating flap fitted with a retaining means positioned therein, said insulating flap being of at least equal size to said contact members, said insulating flap being capable of being rotated through 180* to fully expose and make available, alternately, each of the contact members.